Garza was born in Wasco, California to parents who both emigrated from Mexico. Garza and his family moved to North Dakota where he attended high school and played baseball, basketball, and track. He continued to play basketball in college for two years at the University of Jamestown, as a point guard. He eventually earned a degree in exercise science and personal training at the University of North Dakota. While Garza was in college, he worked two jobs at a factory making windmill blades and also did an internship at a gym.

After leaving the UFC, Garza fought in smaller, outside promotions. Before his Ultimate Fighter fight with Michael Johnson had even aired on television, Garza faced William Joplin, winning via unanimous decision.[2] The fight, which was predominantly stand-up based, saw Garza break the nose of Joplin, before taking control of the fight.[9]

Garza was then signed by the UFC's sister promotion, World Extreme Cagefighting. Replacing Jason Reinhardt, Garza stepped up to face Tiequan Zhang on the undercard of WEC 51 on 5 days notice.[7] He lost the fight via submission in the first round.

In October 2010, World Extreme Cagefighting merged with the Ultimate Fighting Championship. As part of the merger, all WEC fighters were transferred to the UFC.[10]

Garza made his UFC and featherweight debut against Fredson Paixão at The Ultimate Fighter: Team GSP vs. Team Koscheck Finale.[11] This was the first ever featherweight fight in the UFC. Garza knocked Paixão out 51 seconds into the first round with a flying knee. After being unconscious for nearly two minutes, Paixão was on his back for close to four minutes while being given oxygen, before being placed in a neck brace and carried out on a stretcher. Garza earned Knockout of the Night honors for the performance.[12]

Garza defeated Yves Jabouin on April 30, 2011 at UFC 129 via first round submission due to a flying triangle choke.[13] The finish earned him Submission of the Night honors and $129,000.

Shortly after his release from the UFC Pablo relocated to Oslo, Norway. Although currently unsigned, It is expected he will receive offers from the elite European MMA promotions such as Britain's Cage Warriors and BAMMA or Sweden's Superior Challenge.